PA surgery Flashcards
What are the indications for periapical surgery?
Indications for endodontic microsurgery are (Kim, Kratchman & Guess 2010; von Arx 2011; Chong & Rhodes 2014):
1. Conventional root canal re‐treatment could not
be performed or failed (apical lesion develops or
does not heal).
2. Persistent symptomatic cases after root canal
treatment and/or conventional re‐treatment.
3. Conditions require surgical invention such as
non‐negotiable canals (due to calcification, ledge, transportation, or irretrievable materials in the root canals), perforation repair, material out of apex, and biopsy.
What are the flap designs for periapical surgery?
The most often used flap is a full mucoperiosteal flap. It is formed by intrasulcular incision along the contours of the teeth with one vertical releasing incision (triangular flap) or two vertical releasing incisions (rectangular flap) extending to the buccal vestibule.The vertical releasing incision should extend at least one tooth anterior and one tooth posterior of the treated tooth. A full mucoperiosteal flap provides excellent visualization and access to the surgical site.
The papillary‐based flap is designed to preserve the interdental papilla. It prevents papillary recession and is often considered in aesthetically sensitive regions (Velvart, Ebner‐ Zimmerman & Ebner 2004).
A limited mucoperiosteal submarginal (Ochsenbein‐Leubke) flap is formed by a horizontal scalloped incision in attached gingiva with one or two vertical releasing incisions. At least 2 mm of attached gingiva should be retained.This flap is recommended to preserve the gingival margins around crowned teeth.
A limited mucoperiosteal submarginal curved (semilunar) flap is a curved incision beginning just beneath the vestibular fold, extending coronally into attached gingiva and curving back into the vestibule. It has limited surgical access and is associated with scar formation; thus, the semilunar flap is not recommended for endodontic microsurgery (Chong & Rhodes 2014).
What are the principles of root‐end resection, root‐end cavity preparation, and root‐end filling?
Root‐end resection (also called apicoectomy) is the surgical removal of a 3 mm portion of the root end.The purpose is to remove uncleaned apical ramifications and lateral canals.The resected root end is inspected under microscope for possible missed canals, dentin cracks, and isthmuses (Kim & Kratchman 2006; Kim et al. 2010).
The root‐end cavity is prepared with ultrasonic tips to a depth of 3 mm (Kim & Kratchman 2006; Kim et al. 2010). The purpose is to remove the intracanal filling materials and irritants and create a cavity to receive a root‐end filling. Isthmuses need to be cleaned and included in the root‐end cavity. A root‐end filling places a root‐ end filling material into the root‐end cavity to provide an apical seal. An ideal root‐end filling material should adhere to dentinal walls, be dimensionally stable, radiopaque, biocompatible, and without leakage. MTA is the usual choice of root‐end filling material due to its biocompatibility and ability to induce cementum formation on its surface (Torabinejad et al. 1997).
Intermediate restorative material (IRM) and super ethoxybenzoic acid (super EBA) are also used as root‐end filling materials (Chong, Pitt Ford & Hudson 2003; Kim et al. 2016). Recently EndoSequence® BC root repair material and Biodentine® have been introduced as root‐end filling materials (Caron et al. 2014; Shinbori et al. 2015).
What advancements have been made in periapical surgery?
Periapical surgery has been greatly advanced by the introduction of endodontic microscope and microinstruments, especially ultrasonic tips (Kim & Kratchman 2006; Kim et al. 2010; Setzer et al. 2010; Setzer et al. 2012). The endodontic microscope is equipped to examine the operating field with high magnification and focused illumination. The benefits of using this microscope include clear identification of apices, smaller osteotomy, and inspection of the resected root surface for isthmuses, additional canals, and dentinal cracks (Kim & Kratchman 2006; Kim et al. 2010; Setzer et al. 2010; Setzer et al. 2012). The use of ultrasonic tips with the help of the microscope’s magnification makes it possible to prepare a 3 mm depth root‐end cavity following the long axis of the canal on a shallow beveled root end (Kim & Kratchman 2006; Kim et al. 2010). The advancement of periapical surgery has also been aided by the development of good sealing and biocompatible root‐end filling materials such as MTA (Torabinejad et al. 1997).
What are the success rates of periapical surgery?
Periapical surgery has success rates of over 90% (Rubinstein & Kim 2002; Chong et al. 2003; Tsesis et al. 2006; Christiansen et al. 2009).
The Toronto study found the prognosis was better in patients older than 45 years, with teeth having inadequate root‐filling length, and with teeth having crypt size smaller than 10 mm in diameter (Barone et al. 2010).
The meta‐analysis studies found the outcome was better when using higher magnification (Setzer et al. 2010; Setzer et al. 2012) and in teeth without preoperative symptoms, teeth with good density root canal filling, and teeth with no or size less than 5 mm apical lesion (von Arx, Penarrocha & Jensen 2010).
Teeth with a buccal bone plate more than 3 mm high had a higher success rate than teeth with a buccal bone plate less than 3 mm (Song et al. 2013).
MTA as a root‐end filling material has a higher healing rate than adhesive resin composite (von Arx, Hanni & Jensen 2014) and shows no significant difference compared with super EBA and IRM.
Periapical re‐surgery also has a very high success rate (93%) (Chong et al. 2003; Kim et al. 2016). The common causes of failure of apical surgery were no root‐end filling and incorrect root‐end preparation, that is away from the long axis of the canal and has insufficient depth of less than 3 mm (Song, Shin & Kim 2011).
